Production of lubricants containing lead soap of hydrogenated ricinoleic acid



Patented Jan. 19, 1943 PRODUCTION OF LUBRICANTS CONTAININ G LEAD SOAP OF HYDBOGENATED RICINO- LEIC ACID Harold M. Fraser, New Orleans, La, assignor to International Lubricant Corporation,

New

Orleans, La a corporation Louisiana No Drawing. Application July 25,1940, Serial No. 347,532

23 Claims.

The present invention relates to the production 01' lubricants, and more particularly to the production of lubricants containing a lead soap of a hydroxy-stearic acid, the invention in its preferred form being directed to a lubricant containing a lead soap of a 12 hydroxy-stearic acid, the latter also being herein termed a lead soap of hydrogenated ricinoleic acid. The lead soap which may be incorporated in the lubricating medium in accordance with the present invention may be a lead soap of a monohydroxy-stearic acid, the acid being typified by hydrogenated ricinoleic acid, or a lead soap of a polyhydroxystearic acid.

While in the preferred form of the invention it is desired to provide greases having incorporated therein a lead soap of a hydroxy-stearic acid, the grease may have incorporated therein such a soap, together with a soap in which the hydroxy-stearic acid, and especially the 12 bydroxy-stearic acid is coupled with an organic base, as hereinafter set forth.

In accordance with the present invention, there is produced a grease having present a lead soap of a hydroxy-stearic acid, and in the preferred form of the invention a grease having present a lead soap of the 12 hydroxy-stearic acid, irrespective of how the same is produced, said soap in the preferred form of the invention being produced by first hydrogenating ricinoleic acid, and then saponifying the hydrogenated ricinoleic'acid. In general, it may be stated that said greases have a splendid body, and are characterized by suitable hardness, a high melting point m the presence of a small percentage of soap, insolubility in water,

and a high film strength.

In accordance with the present invention, the lubricating medium has, for example, a grease or a viscous lubricating medium, may have incorporated therein lead soaps of polyhydroxy-stearic acid, said soap being produced by the metathesis or double decomposition method. For example,

the lead soap of dihydroxy-stearic acid, the hydroxy groups being in the 9 and 10 positions, was prepared by. the methods set forth," and the resulting soap was introduced into a hydrocarbon oil. This soap was somewhat soluble in the hydrocarbon itself, and the solubility was better at 300 F. On heating to a higher temperature, there was some degradation of the lead soap which resulted in a grease which on cooling possessed the characteristics of a low solubilized content oi lead soap.

Since these lead soaps are only slightly soluble in the lubricant base, even at high temperatures,

it is necessary when incorporating the soap in the lubricant base, as for example a mineral oil, to provide a carrier similar to that disclosed in Fraser application, Serial No. 268,781, filed April 19, 1939, and co-pending application, Serial No. 347,533, filed concurrently herewith.

It may be stated that the presence of more than one hydroxy group in the lead soap of a hydroxy-stearic acid reduces the solubility of the soap in the lubricant base. Because of this reduced solubility, such lead soaps should preferably be added to the lubricant base in amounts under 1%, although when a carrier is used the amounts may be increased. However, it is desired to point out that the lead soaps of the polyhydroxy-stearic acids as a class exhibit inferior jellying characteristics as compared to the lead soap of the monohydroxy-stearic acid, as far as the effects upon the mineral oil base is concemed.

It is desired to point out that irrespective of whether the lubricating medium is a grease or a viscous non-solid lubricating medium, it may have incorporated therein a mixture of a lead soap of a mono or polyhydroxy stearic acid, together with an organic soap of a mono or polyhydroxy-stearic acid. In other words, instead of having the lead component coupled to the acid constituent, the hydroxy-stearic acid may have coupled thereto an organic base. For example, instead of using lead, the hydroxy-stearic acid may have combined therewith any of the ethanolamines, such as the di or triethanolamines to produce an amino soap. In the more specific aspect of the invention, the lead soap of the 12 hydroxy-stearic acid, which is herein termed the lead soap of hydrogenated ricinoleic acid may have mixed therewith an organic soap of the 12 hydroxy-stearic acid.

In general, it may be stated that in the lubricatingmediums herein disclosed, all or part of the lead soap of any of the hydroxy-stearic acids herein set forth may have all or part of the lead soap substituted by a soap made by saponifylng any of the herein described hydroxy-stearic acids with an organic base to produce what may be hydrogenated ricinoleic acid, that is from about /4% to 4%, greases containing up to 50% of this soap, which are hard greases, may be used as block greases, on railroad axles, collander bearings, and for other purposes where it is known that a hard grease is necessary or desirable.

It has been further discovered that the hardness of the grease increases with the increase in its content of the lead soap of hydrogenated ricinoleic acid. For example, when the grease contains above 4 or 5% of this lead soap, it becomes increasingly diflicult to mill the grease, due to its hardness. Therefore, in order to produce a grease of normal hardness, it is usually desirable that the lead soap of hydrogenated ricinoleic acid be present between the limits of and 2 to 3%, although the soap content may be somewhat higher, as above set forth.

It has also been discovered that when the grease is compounded from high viscosity naphthene base oils, when the lead soap of hydrogenated ricinoleic acid, as for example hydrogenated castor oil, is incorporated in the naphthene base oils, the resulting greases are less granular in the cooling pan after pouring, and produce more quickly a smoother grease in the milling operation than when the non-naphthene base oils are used, and therefore where it is desired to produce a grease which has a minimum amount of granularness, a lead soap of hydrogenated ricinoleic acid is incorporated in a naphthene base oil.

It has also been discovered that certain addition agents added to the grease before pouring produce a smoother texture in the pan, and further, function to reduce the milling timeof the grease after cooling.

In accordance with the present invention, the

exture of the grease having the lead soap of hydrogenated ricinoleic acid incorporated therein may be controlled by controlling the rate of cooling of the grease, the relationship between the texture of the grease to the rate of cooling being just the opposite to that occurring when ordinary greases, such as aluminum, lime or soda base greases, are cooled quickly or slowly.

Not only may the grease of the present invention have incorporated therein the lead soap of hydrogenated ricinoleic acid, but there may also be incorporated in the grease the other soaps, such as aluminum soaps, lime soaps, or sodium soaps, to thereby form a mixed soap base grease. For example, there may be incorporated in the grease in addition to the lead soap of hydrogenated ricinoleic acid, an ordinary soda soap or a soda soap of hydrogenated ricinoleic acid. Instead of adding a soda soap, there may be added a lime soap which may be the ordinary lime soap or the lime soap of hydrogenated ricinoleic acid. There may be present in the grease a plurality of soaps, one of which is the lead soap of hydrogenated ricinoleic acid, the remaining soaps either being the ordinary prior art soaps or the metal soaps of hydrogenated ricinoleic acid, as for example those derived from hydrogenated castor oil.

If the lead soap of hydrogenated ricinoleic acid is in the predominance, the grease may be termed a lead base grease, and if the soda soap, for example, is in the predominance, the grease may be termed a soda base grease, but it will still have present a substantial proportion of the lead soap of hydrogenated ricinoleic acid.

It is desired to point out that a grease having incorporated therein a small percentage of a lead soap of hydrogenated ricinoleic acid may have its melting point increased by adding thereto a proportion of a sodium soap which may be the ordinar sodium soap or the sodium soap of hydrogenated ricinoleic acid. One of the outstanding novel features of the present invention is that by the incorporation of a lead soap of hydrogenated ricinoleic acid in the grease there is produced a harder grease than would have been produced by incorporating the same percentage of any of the prior art soaps, and simultaneously the melting point of the grease is increased. More specifically, if there is incorporated in an oil base 1 to 2% of a lead soap of hydrogenated ricinoleic acid such as castor oil, the resulting grease will have an A. S. T. M. worked penetration of approximately 350. To produce the same worked penetration, it will take 4 to 6% of an ordinary sodium soap, 6 to 8% of an aluminum soap, as for example aluminum stearate, and 8 to 10% of a lime soap.

In view of the above, it may be stated that the primary object of the present invention is to produce a grease having present a lead soap of hydrogenated ricinoleic acid, possessing the advantages above set forth, and other advantages which will appear from the following disclosure.

In the compounding of grease, it is highly desirable that the grease contain the smallest possible soap content compatible with the production of a high grade grease. The reason for this is, first, the smaller the soap content the cheaper the cost of manufacture; and second, the higher the percentage of lubricating oil incorporated in the grease, the better the lubrieating grease.

Different kinds of greases require different percentages of soap to yield greases of the same consistency. For example, in order to obtain a grease of an A. S. T. M. worked penetration of 350, it is necessary to use approximately the following soap content dissolved in the oil constituent of each grease:

Table I Melting sgorzgsgn 111815131 point or grease Per cent Per cm! Lime soap 8 to 12 88 to 92 200 Soda soap 4 to 6 94 to 96 300 Aluminum stearate 5 to 7 93 to 200 If approximately 1% of a lead soap of hydrogenated ricinoleic acid, such as hydrogenated castor oil, is incorporated in the mineral oil of the grease, the latter has a worked penetration of 350. In other words, an exceedingly small proportion of the lead soap of hydrogenated ricinoleic acid produces a grease having the same or a much higher worked consistency than an equivalent grease using the same type of mineral oil but having present the ordinary lime soap, soda soap, or aluminum soap, as for example aluminum stearate. The melting point of the 1% lead soap grease is approximately 250 F., which is a much higher melting point than that possessed by either the lime base greases or the aluminum stearate greases. While the soda base greases have higher melting points than the greases containing the lead soap of hydrogenated ricinoleic acid, the soda base greases possess the undesirable characteristic of emulsifying readily with water. On the contrary, a grease containing the lead soap of hydrogenated ricinoleic acid, as for example that obtained from castor 011, does not emulsify easily with water.

The invention will be illustrated by a number of specific examples. However, before doing so, it is desired to state that the hydrogenated cas tor oil which is saponified by a suitable lead compound is the usual commercial product having the following characteristics:

Titre 64.5 Sapon. number 178 Iodine number 2. '7

The hydrogenated castor oil is a solid and has a melting point of about 72 C.,- which indicates that the hydrogenation process has been practically carried to completion. The best results in practicing the present invention will be obtained by producing a lead soap of substantially completely hydrogenated castor oil. However, the castor oil may be only partially hydrogenated and still may be used. Stated dlfierently, the higher the degree of hydrogenation of the castor oil, the better results obtained when the lead soap thereof is incorporated in the lubricant Solution B is added to solution A and heated until saponification is substantially complete. Thereupon, solution C containing lead acetate is added and the mixture stirred for live or ten minutes. Just enough of acetic acid is added to make the mixture react acid to phenolphthalein. There is then formed as a white precipitate, the lead salt of hydrogenated rlcinoleic acid. The

taining the lead soap oi hydrogenated rlcinoleic acid. For example, as high as 10% of lead oleate may be added to the above lead soap of hydrogenated castor oil, and the mixed soap content in the final grease reduced to 2%, without appreclably affecting the properties of the grease.

In compounding greases containing various percentages of the lead soap of hydrogenated ricinoleic acid, the lead soap, as above prepared, was dissolved in a 2000 viscosity at 100 F. Saybolt vis. oil. Fifteen pound batches were made and poured in a metal pan, 11 inches by 15 inches deep, and allowed to cool. The temperature of the grease when poured was about 300 F. In general, it may be stated that the grease having present the lead soap of hydrogenated rlcinoleic acid should be heated above 240 F., in order that the grease be thoroughly melted, and then should be poured at above 275 F., and preferably at between 310 to 325. The grease containing the lead soap of hydrogenated castor oil may be heated to as high as 400 F., and the properties of the grease are not adversely affected, with the exception that there may be some darkening of the grease. In order to effect the cooling of the grease, the pan in which the latter was contained was placed in a box and cooled to room temperature in a period varying between 12 to 14 hours.

reaction-mixture is filtered, and the resulting lead soap washed several times with hot water and dried approximately at a temperature of 105 C. This soap contained about mi oi lead. The lead soap of hydrogenated rlcinoleic acid may also be prepared by reacting the following constituents:

Grams D. Fatty acids of hydrogenated castor oil 100 100 vis. at 100 Saybolt coastal oil 50 E. Lead oxide 35 100 coastal oil 50 Mixture D is heated until the hydrogenated fatty acids of the castor oil are melted in the mineral oil. Mixture E is then thoroughly stirred cold and then added to mixture D, maintaining the temperature of the mass at about 00 to 325 F. Mixture E should be added slowly to keep the reaction from proceeding too rapidly. When the entire quantity of mixture E has been added, the temperature should be approximately 325, and the stirring is preferably continued for several minutes. Thereafter, there is added an additional 35 grams of 100 coastal oil. v

The above grease which contains approximately 50% of the lead soap of hydrogenated ricinoleic acid can beeither cooled or dissolved in oil for producing grease at a later time, or enough mineral oil may be added immediately to brin the soap content down to the desired percentage. Other types of lead soap such as lead oleate and the like may also be added to the grease con- Thecooled greases are very hard and slightly granular in appearance. A grease containing 2% of the lead soap of hydrogenated ricinoleic acid had an unworked penetration of 101.

The grease after being passed through a mill and screened'was smooth, transparent, and of somewhat stringy texture. Three different batches of greases having difierent soap contents were characterized by the following properties:

Referring to the effect produced by cooling greases made up as above set forth, it may be stated that the quicker the grease is cooled, the softer it becomes. If a 15 lb. batch of-the grease be exposed to the air and is cooled in a few hours, say 3 to 5 hours, the grease at the top and sides of the pan is soft and mushy. However, when the grease is cooled at a slower rate, as for example from 310 F. to room temperature in 12 to 16 hours, the resulting grease had a much smoother and a much firmer texture. If the grease is cooled much more slowly, from 310 F. to room temperature, said cooling occupying a period approximately 25 to 30 hours, the grease was more grainy in appearance. The above results are just the opposite of what is obtained when ordinary greases such as aluminum, lime or sodium greases which have non-hydrogenated bases are cooled quickly or slowly.

Referring to the grease of the present invention containing as its essential soap component a lead soap of hydrogenated rlcinoleic acid, it is desired to point out that the moisture content of the grease should be less than .01%, and the b'cerine content less than 0.5%. The free fatty acid may vary considerably, without affecting the physical properties of the grease to any substantial extent. Free fatty acid up to 0.5% in a grease containing 4% of the lead soap of ricinoleic acid did not effect any substantial change in the structure of the grease.

Various treatment agents may be added to the grease to produce a, smoother texture therein, these addition agents also functioning to reduce the milling time after the grease was cooled. While the addition agents may be added to the grease during various stages of the manufacture of the grease, it is preferable to incorporate the addition agents in the grease just before it is poured. One agent which gave very satisfactory results is that known as butyl carbitol, which is a trade name of the substance manufactured by the Carbide & Chemical Corporation of New York. The chemical name of this agent is monobutyl-ether of diethylene-glycol. I'his material when used in amounts of 1 5 of 1% gave very satisfactory results. Higher alcohols, such as octyl, and iso-octyl alcohol such as ethyl hexanol, and solid alcohols such as cetyl, also function as texture-modifying addition agents. Th ethanolamines also function to produce a smoother texture. While either the mono, di or triethanolamine may be used, or mixtures of the same may be used, it is preferred to use triethanolamine and 1 6% of the triethanolamine gives satisfactory results. Instead of using the ethanolamines, the ethanolamine soaps may be used, as for example triethanolamine stearate. Cyclohexylamine may also be used to give a smoother textured grease. Preferably, it is desired to incorporate this addition agent in an amount equivalent to 0.2%, taken on the weight of the finished grease. All of the percentages above set forth are taken on the weight of the finished grease. 0.2% oleic acid also gave good results in functioning to eliminate the milling of the grease. The addition of 0.5% of acetylated castor oil functions satisfactorily to produce a smoother textured grease.

While certain percentages of these texture modifying addition agents have been set forth as the most satisfactory, it is obvious that these percentages may be varied considerably and still come within the spirit of the invention. As a general rule, it is only necessary to add from about 1 6% to 1% of the texture-modifying agent, although in some circumstances this may be increased from 2 to 4%. It is also desired to point out that the addition of the amines reduces to some extent the free acid content of the grease.

Mixed soap base greases containing the lead soap of hydrogenated ricinoleic acid, together with other soaps, were prepared by taking a grease containing 2% of the lead soap of hydrogenated ricinoleic acid, as for example that obtained from hydrogenated castor oil, and mixing therewith a soda base grease containing 4% of a soda soap. These greases were mixed when cold in various proportions. 75% of the grease containing the lead soap of hydrogenated ricinoleic acid was mixed with 25% of the soda soap grease having a Ubbelohde melting point of 255 F. The final mixed base grease carried a total soap content of 2 of which 1 9 was the lead soap of hydrogenated castor oil and 1% was the ordinary soda soap. In place of the ordinary soda soap there may be substituted a soda soap of hydrogenated castor oil. Another grease was prepared by mixing 62 of the grease containing 2% of the lead soap of hydrogenated ricinoleic acid with 37/2% of the grease containing 4% of a soda soap. The final grease which had a Ubbelohde melting point of 300 F. and carried 3% total soap content, had incorporated therein 1% of a lead soap and 2% of the soda soap.

Another grease was made by mixing 25% of the grease containing 2% of the lead soap of hydrogenated castor oil and 75% of the grease containing 4% of the soda soap. The resulting grease which carried 3%% total soap content, and had a Ubbelohde melting point of 305 F. carried of the lead soap and 3% of the soda soap.

The above greases were smooth, transparent and of good appearance. It the above mixture of greases are heated above the melting point and cooled, the heat treated greases are much softer and grainier than if the greases are mixed cold, and in view of the above, it is desired that the greases be mixed in a cold state, although heat may be employed under some circumstances.

Another mixed base soap grease was made by mixing 50% of the grease containing 2% of the lead soap of hydrogenated castor oil with 50% of aluminum stearate grease containing 5% of aluminum stearate. The resulting grease which contained 1% of the lead soap and 2 of the aluminum stearate soap had a Ubbelohde melting point of 205 F. The two greases were mixed in the cold to provide a smooth, transparent grease of good appearance.

Another mixed soap base grease was prepared by mixing in the cold 50% of a grease containing 2% of the lead soap of hydrogenated castor oil with 50% of a lime base grease containing 10% of a lime soap. The resulting grease containing 1% of the lead soap of hydrogenated castor oil and 5% of a lime soap of fatty acids, had a melting point of 205 F. The mixed grease was smooth, translucent and of good appearance. Another grease was made by mixing together equal parts of a grease containing Vz% of a lead soap of hydrogenated castor ofl and a soda base grease containing 10%% of soda soap. The resulting grease was melted together and poured into a pan at 350 F. It was then cooled and found to have a melting point of 336 F. and an A. S. T. M. worked penetration of 240. The grease contained a total soap content of 11%, of which was a lead soap, and the remainder was the soda soap. The free alkali content of the resulting grease, as determined by the regular A. S. T. M. method was .08%, and the grease had a Saybolt oil viscosity of 500 seconds at F. When rolled in ball bearings, it retained the same approximate consistency for a working time of two hours.

In the above examples, the soda soap present in the grease and the lime soap present in the grease were made respectively with the ordinary fatty acids, but it is desired to point out that instead of using the ordinary fatty acids, there may be substituted therefor hydrogenated castor oil or the like. In other words, the mixed soap base greases may contain not only the lead soap of hydrogenated castor oil, but also the soda soap of hydrogenated castor oil and the lime soap of hydrogenated castor oil.

While for the most part the lubricant base used in compounding the greases may be a mineral oil, it is within the province of the present invention to use an animal or vegetable lubricant base, or mixtures of the same, together with addition agents including rosin, such as set forth in co-pending application, Serial No, 347,533.

In view of the above disclosure, it may be pointed out that in accordance with the present invention there is provided a lubricating grease containing a lubricant base, together with a lead soap of hydrogenated ricinoleic acid. This lead creases. In general, the herein described grease containing 1 to 4% of the lead soap of hydrogenated ricinoleic acid has a melting point varying between 240 to 260 F.

In one aspect of the invention, there is provided a lubricating grease containing a lubricant base, together with a plurality of soaps, one of which is a lead soap of hydrogenated ricinoleic acid, said soap being present in a predominating proportion as compared to the other soaps, or in a minor proportion as compared to the other soaps. While the percentages of the difierent soap constituents may vary, in general there may be present in the grease up to 50% of soap, substantialLy all of which may be a lead soap, or 1 the soap content may be a mixture of a lead soap, together with a soap of a different base, as for example, a lime base soap. More specifically,

the grease may contain of the herein described lead soap together with 25% of a dinerent soap. In one form of the invention there may be present in the grease from 1 to 4% of a lead soap, together with 1 to 6% of a difierent base soap, as for example, a lime base soap.

Where the grease contains a plurality of soaps, one of which is a lead soap of a hydroxy-stearic acid, as for example, the lead soap of 12 hydroxy-stearlc acid, otherwise termed a lead soap of hydrogenated ricinoleic acid, at least one of the other soaps may be a soap of a hydroxystearic acid, as for example the sodium soap of hydrogenated ricinoleic acid, and in the more limited form of the invention said soap may be present in the grease in an amount varying between 1 to 3%, and if desirable, the lead soap of the hydroxy-stearic acid, as for example the lead soap of 12 hydroxy-stearic acid may be present with the soda soap in an amount varying between 1 to 2% it being pointed out that the soda soap functions to increase themelting point of the mixed base grease.

In accordance with the present invention, the lubricating medium, as for example, a grease, may have incorporated therein a lead soap of a 10 hydroxy-stearic acid, as for example the lead soap of this acid. This product may be manufactured by several accepted methods of preparation, including a metathesis reaction utilizinga soluble lead salt such as lead acetate in reaction with the sodium soap of the 10 hydroxystearic acid. The lead soap of the 10 hydroxystearic acid has a somewhat softer texture and a lower solubility in the mineral oil bases in which the lead soap of the 12 hydroxy-stearic acid was incorporated. Further, the lead soap of the 10 hydroiw-stearic acid does not gel and/or harden the grease in which is incorporated to the same optimum degree as that which occurs when the lead soap of the 12 hydroxystearic acid, the acid of which has been produced by acid oxidation or by other methods, is incorporated in the grease.

In accordance with the present invention there has also been incorporated in a lubricating medium soaps of the polyhydroxy-stearic acids.

For example, the soaps may be formed from hydroxy-stearic acids in which the hydroxy groups are in the 9 and 10 carbon position. The polyhydroxy-stearic acid may be prepared by oxidation and subsequent hydroxylation of oleic acid. The soaps of this acid may be prepared by metathesis, as above set forth, and by direct combination of the above fatty acid with oxides of metals as, for example, heating the fatty acid dispersed in a hydrocarbon oil to which there has been added a metal constituent, as for example, lead oxide or litharge. While the metathesis method and the above method produce slightly difierent end products, the general behavior is substantially the same.

While it has been statedthat the soap of the hydroxy-stearic acid, including 12 hydroxystearic acid which is incorporated in the lubricant or grease, is a metal soap as, for example, a lead soap, it is within the province of the present invention in some cases to substitute for the metal base an organic radical to thereby produce an organic soap of the hydroxy-stearic acids, and more specifically an organic soap of 12 hydroxy stearic acid, or an organic soap of dihydroxy-stearic acid. For example, instead of using a metal constituent, any of the hydroxy fatty acids, and more specifically the 12 hydroxystearic acid, otherwise herein termed hydrogenated ricinoleic acid, may be combined with ethanolamine to produce an amino soap which when incorporated in the lubricating medium, especially the fluid viscous lubricants, gives desirable results. This phase of the invention is not limited to the use of the organic soap forming medium ethanolamine. This is merely exemplary of suitable organic radicals having basic properties which may be combined with the hydroxy-stearic acid. I

It is also within the province of the present invention to provide a grease in which the soap constituent is a mixture of a lead soap of hydroxy-stearic acid, including 12 hydroxy-stearic acid, and an organic soap of a hydroxy-stearic acid, including 12 hydroxy-stearic acid, the organic radical being typified by ethanolamine or the like. In other words, any of the hydroxystearic acids, including the monohydroxy-stearic acid, the 12 hydroxy-stearic acid, and polyhydroxy-stearic acid, including dihydroxy-stearic acid, may be partially or totally saponified with an alkylamine or an arylamine, and the resultingsoap mixed with any hydroxy-stearic acid, including those herein described, and more particularly with the metal soap of i2 hydroxystearic acid, including the lead soap thereof. In this phase of the invention, it is also obvious that other organic bases may be coupled with the hydroxy-stearic acid to produce a soap.

What I claim is:

1. A lubricating grease containing a lubricant base and a lead soap of hydroxy-stearic acid.

2. A lubricating grease containing a lubricant base and a lead soap of 12 hydroxy-stearic acid.

3. A lubricating grease containing a lubricant I base, and a lead soap of hydrogenated ricinoleic acid.

7. A lubricating grease containing a lubricantv base, and from A of 1% to 5% of a lead soap 0! 12 hydroxy-stearic acid.

8. A lubricating grease containing alubricant base together with a relatively small percentage of a lead soap of hydrogenated ricinoleic acid, said grease having a melting point of approximately 250 F. and an A. S. T. M. worked penetration varying between 350 and 250.

9. A lubricating grease containing a lubricant base together with 1 to 4% of a lead soap of 12 hydroxy-stearic acid, said grease having a melting point varying between 240 and 260 F.

10. A lubricating grease containing a lubricant base together with 1% of a lead soap of hydrogenated ricinoleic acid, said grease having a melting point of about 250 F.

11. A lubricating grease containing a naphthene lubricant base and a lead soap of hydrogenated ricinoleic acid, the presence of said base inhibiting any tendency of the grease to cool to a granular state.

12. A lubricating grease containing a lubricant base together with a lead soap of 12 hydroxystearic acid and a metal soap of the fatty acids, the lead soap being present in a predominating proportion.

13. A lubricating grease containing a lubricant base together with a plurality of soaps, one of which is a lead soap or hydrogenated ricinoleic acid, said soap being present in a minor proportion as compared to the other soap constituents.

14. A lubricating grease containing a lubricant base, together with a lead soap of 12 hydroxystearic acid and an aluminum base soap.

15. A lubricating grease containing a lubricant base together with a lead soap of 12 hydroxystearic acid and a soda base soap.

16. A lubricating grease containing a lubricant base together with 1 to 4% of a lead soap of hydroxy-stearic acid and 1 to 6% or a different base soap.

17. A lubricating grease containing a lubricant base, together with a plurality of soaps. one or which is a lead soap of hydrogenated ricinoleic acid, and at least one or the other soaps being a soap of hydrogenated ricinoleic acid.

18. A lubricating grease containing a lubricant base, together with a lead soap of hydrogenated ricinoleic acid, and a soda base soap of hydrogenated ricinoleic acid, said soap being present in an amount varying between 1 and 3%.

19. A lubricating grease containing a lubricant base together with a lead soap or 12 hydroxystearic acid and a small amount of another polyvalent metal soap.

20. A lubricating grease containing a lubricant base together with a relatively small percentage of a lead soap of 12 hydroxy-stearic acid, said grease having a melting point of approximately 250 F. and an A. S. T. M. worked penetration varying between 350 and 250.

21. A lubricating grease containing a naphthene base oil and a lead soap of hydroxy-stearic acid.

22. A lubricating grease containing a naphthene base oil and a lead soap or 12 hydroxystearic acid.

23. A lubricating grease containing a lubricant base and from about one-fourth oi! one per cent to about five per cent of a lead soap of hydroxystearic acid.

HAROLD M. FRASER. 

